Czech Polar Reports

Multi-disciplinary geoscientific expedition to Woodfjorden, NW Svalbard: Field sites, methods, and preliminary results

2024-03-12T16:47:03+01:00

The Woodfjorden area of northern Spitsbergen (NW Svalbard) offers access to the world’s northernmost onshore thermal springs, extinct Pleistocene alkali basaltic volcanoes and Miocene flood basalts including extensive hyaloclastites. In July 2023, we undertook a 14-day international multi-disciplinary geoscientific expedition to Woodfjorden-Bockfjorden to investigate the Cenozoic geological evolution of the area. The expedition objectives spanned a wide range of scientific topics from sampling of fluids and gas in the thermal springs to constraining the lithosphere by acquiring magnetotelluric data and sampling volcanic rocks. More specifically, we have 1) conducted gas, fluid and travertine sampling at the thermal springs of Gygrekjelda, Jotunkjeldene and Trollkjeldene, 2) mapped and sampled the Quaternary volcanic centers at Sverrefjellet and Halvdanpiggen, 3) sampled the Miocene basalts of the Seidfjellet Formation along seven profiles plus the underlying Devonian sedimentary rocks, 4) acquired magnetotelluric data at 12 stations along both coasts of Woodfjorden and Bockfjorden and 5) collected extensive digital geological data (digital outcrop models and photospheres) using unmanned aerial vehicles (UAVs; also known as drones). The collected samples are currently being analyzed for, amongst others, petrology, geochemistry and geochronology. In this contribution, we report on the expedition’s background, scientific objectives and present selected preliminary results such as field parameters from the thermal springs (temperature, pH, electrical conductivity), magnetic susceptibility of volcanic rocks and digital outcrop models plus photospheres.

Analysis of dental care in Antarctic crews: Dental problems, case studies and treatments

2024-03-13T09:29:44+01:00

Dental issues are relatively common in Antarctic stations both during short-term and long-term expeditions. In overwintering crews, dental problems may reach 10-15% of overall medical cases. In the expeditions working only during the austral summer season, the proportion of dental problems is lower, typically not exceeding 5%. In our study, facilities available recently for dental care in Antarctica, considering seasonal – and year-round operated stations, are overviewed. Several case studies are reported in order to show the treatment of the most frequent dental problems that happen in Antarctica in short-term (seasonal) and long-term (overwintering) expeditions. Our study brings an analysis of dental cases reported by Czech Antarctic Program within 15 years (2008-2015) and the Brazilian Antarctic Program (2018-2023). New trends in dental care in Antarctica are discussed including telemedicine and integrated systems.

Invasive species Dreissena polymorpha in the Northern Dvina River estuary

2024-03-13T09:52:05+01:00

The features of distribution of Dreissena polymorpha (Pallas, 1771) in the northeastern part of the range and in the estuary part of the Northern Dvina River are described. Based on the earlier studies of different authors, it was suggested that the population of this mollusk is independent and self-replicating. To prove that, our study provides some population characteristics of D. polymorpha settlements. Mollusk samples were taken in the summer in 2018-2021. The research was conducted in the upper delta and in the lower part of the estuary section in order to evaluate the agglomeration. In total, 1538 individuals were selected from three sites of collection. A set of morphometric measurements was performed. Intra-population diversity was studied, weight and length of D. polymorpha individuals were evaluated. Statistically significant differences were found between the individuals living in the upstream estuary and those living in the Northern Dvina River delta, which is explained by the differences caused by of abiotic factors such as current velocities, availability of suitable substrates, amount of nutrients. There were no significant differences in the presented parameters between the second and third sampling site, due to the relative proximity of the sampling stations. The importance of further study of the biology and ecology of this mollusk in the North Dvina River basin is shown.

Deep Learning-based marine species detection and classification framework for biomonitoring in the Arctic fjords, Svalbard

2024-03-18T16:10:58+01:00

The effects of ongoing climate change have caused a poleward shift in the distribution of species due to the rapidly rising water temperatures. This calls for an immediate need to assess and document the extent of climate change-driven animal migrations occurring in the Arctic waters. However, the extreme climatic conditions and the remoteness of the region makes biomonitoring tedious in the Arctic ecosystem. The present study puts forward a deep learning-based analysis of a large underwater video dataset that was captured from the Arctic region. The dataset was acquired using underwater cameras mounted on custom-made stainless-steel frames. The video footages were collected over a period of 26 days from the Kongsfjorden- Krossfjorden twin Arctic fjords in Svalbard, Norway. The collected data sets were used to train YOLO-based object detection framework (You Only Look Once) for an automated detection of the organisms. The YOLO model employed for the study was found to be very efficient in classifying the underwater images captured from the region. The object detection framework could detect images of Comb jelly, Echinoderm, Sea Anemone and Ulke (Shorthorn sculpin) from the underwater images. The model attained a superior value of Mean Average Precision (mAP), precision, and recall of 99.5%, 99.2%, and 97.4%, respectively.

Determining the breaking points of the trend in long-term changes of air temperature in Barentsburg (Svalbard)

2024-03-13T10:10:22+01:00

Changes in the average annual surface air temperature (SAT) in Barentsburg (Svalbard) for the period 1899-2022 are considered. The SAT increases at an average rate of 0.34°C/10 years. The warming process is not continuous and consists of two periods of cooling and two periods of warming. Statistical methods have been used to establish the most probable position of the breaking points of the SAT trend: 1917, 1938, and 1968. The recent (“modern”) warming in the region began in the late 1960s, but since 1988, its intensity has doubled.

RNA analysis of the longest living vertebrate Greenland shark revealed an abundance of LINE-like elements in its transcriptome

2024-03-13T10:22:54+01:00

The Greenland shark (Somniosus microcephalus) is an enigmatic species known for its exceptional longevity and extraordinary adaptations to the cold environment. This animal lives in the arctic and subarctic regions of the North Atlantic Ocean. Surprisingly, even though it is a vertebrate with the longest known lifespan, its transcriptome has not been studied yet. Therefore, we isolated and analyzed RNA in the Greenland shark samples. Our findings reveal some important information about the possible genetic mechanisms that could contribute to its longevity. We identified a highly expressed long interspersed nuclear element-like transcript (LINE-like) that is supposed to be associated with extended lifespan and resilience to age-related diseases, possibly through an improved telomere maintenance mechanism. This research not only contributes to our understanding of the biology and evolution of the Greenland shark but could also have implications for human longevity research.

Antiviral activity of Deschampsia antarctica plant extracts in vitro

2024-03-13T11:17:12+01:00

Main objective of research to study the D. antarctica extracts antiviral activity which was grown in vitro and propagated by cloning. The D. antarctica aqueous ethanolic extracts was tested on in vitro models of MDСK – Madin-Darby Canine Kidney cells and PEK – Porcine Embryonic Kidney cells and influenza virus, А/FM/1/47(H1N1) strain and transmissible gastroenteritis virus – porcine coronavirus (TGEV). The antiviral activity of D. antarctica plant extracts (G/D9-1 genotype) on experimental models of influenza viruses and Coronavirus TGEV in vitro was conducted. D. antarctica plant extracts high antiviral activity on influenza viruses and Coronavirus TGEV in vitro was shown.

Response of the climatic mass balance of Hurd and Johnsons glaciers, Livingston Island, to the transient cooling period of the northern Antarctic Peninsula in the early 21st century

2024-03-13T11:33:53+01:00

We calculated and analysed the climatic mass balance of Hurd and Johnsons glaciers, Livingston Island, northern Antarctic Peninsula region, over the period 2002−2016. This period is nearly coincident with the transient period of sustained cooling occurred in the northern Antarctic Peninsula region in the early 21^st century. A positive trend for the climatic mass balance of ~0.5-0.6 m w.e. decade^-¹ was observed, in parallel with a striking negative trend of the equilibrium line altitude of ~ -100-200 m decade^-1, and a positive trend of the accumulation area ratio of ~3-6% decade^-1. Other glaciers monitored in the South Shetland Islands and the periphery of the northernmost Antarctic Peninsula have shown a similar behavior, with the changes observed in the former being more marked.

The 2023 Litli-Hrútur eruption of the Fagradalsfjall Fires, SW-Iceland: Insights from trace element compositions of olivine

2024-03-13T11:46:20+01:00

This study provides data on the trace element composition of olivine from olivine tholeiitic basalts sampled during the July–August 2023 Litli-Hrútur eruption of the Fagradalsfjall Fires in the Reykjanes Volcanic Belt. Chemistry of the Litli-Hrútur olivine is characteristic for volcanic olivine crystals that represent products of magmatic crystallisation. The investigated olivine megacrysts show forsterite (Fo) content in the range of 81 (rims) to 85 (cores) mole percent [defined as Fo = Mg/(Mg + Fe)]. Olivine Ni concentrations (1540–1840 ppm) correlate positively with the Fo contents. In addition, Ca contents show a range from 1890 to 2460 ppm at relatively low Ti concentrations. Olivine from the Litli-Hrútur samples shows an equilibrium with peridotitic mantle melts, yet the data show that the 2023 Litli-Hrútur and the 2022 Meradalir olivine populations crystallised from compositionally more evolved magma batches than olivine crystals from the 2021 Geldingadalir eruption of the Fagradalsfjall Fires. These results imply that magmatic differentiation has taken place between the initial 2021 events and the subsequent 2022 and 2023 eruptions as a result of crystal–liquid fractionation, shifting the overall magma chemistry towards more evolved compositions with time. This implies that fractional crystallisation in sub-alkaline magma reservoirs operates on the scale of years, which is a fundamental advance in our understanding of these common magmatic systems.

Springtime evolution of stratospheric ozone and circulation patterns over Svalbard archipelago in 2019 and 2020

2024-03-13T12:03:24+01:00

The polar vortex was exceptionally intense and persistent in late winter and spring 2020. The unusually cold lower stratosphere subsequently enabled ozone depletion over the Arctic. The behaviour of ozone layer and stratospheric parameters at the Ny-Ålesund station in the late winter and spring 2019 and 2020 were compared to each other by using reanalysed data, ground- and satellite-based observations and radiosonde measurement. The analyses based on the above-mentioned approaches confirmed a close relationship between ozone depletion and stratospheric circulation in 2020, when a strong polar vortex was observed, while in the case of the much weaker 2019 polar vortex such a relationship was insignificant. The deepest ozone decrease was found to occur at the end of March and in the first half of April 2020 at the 100–40 hPa pressure levels.